Process for producing guanamine derivatives



Patented Nov. 17, 1942 UNITED I STATES PATENT. OFFICE 2,302,162 raocsss ron. rnonvomc GUANAMINE nnarvs'rrvns Werner Zerweck and Walter Brenner, Frankfort-- on-the-Main-Fechenheim, Germany; vested in the Alien Property Oustpdlan No Drawing. Application April 17, 1941, Serial No. 388,984. In Germany May 9, 1940 7 Claims.

Our present invention relates to an improved process for producing guanamine derivatives of the general formula:

wherein R stands for a member of the group consisting of an alkyl and the benzyl radicle,

an "aromatic radicle of the benzene-and naphthalene series and a heterocyclic 'radicle of the furane series.

The present improved process consists in heating a mixture of dicyandiamide, a nitrile cor'npound of the formula RCN, wherein R has the aforesaid significance, and a strongly basiccompound.

When using nitrile compounds of a relatively low boiling point the reaction is advantageously carried out in a closed vessel.

Whereas the hitherto known processes convert following examples are given, the parts being by weight and all temperatures in degrees centigrade.

Example 1 A mixture of 84 parts of dicyandiamide, 250

parts of acetonitrile and 16 parts of piperidine is heated for about 5 hours at about 190 to 195 in an autoclave. The crystallizing reaction product is 4.6-diaminoQ-methyltriazin-1.3.5 (acetoguanamine) EH2 fi HzN-C $-CH1 The product has a melting point of 263 c. The yield obtained surpasses. 80% of the theoretical, whereas without the addition of a basic compound such as piperidine there is obtained an impure reaction product melting at 200 to 216 C. in a yield of about 60% of the theoretical. When adding 10 parts of ethylene-diamine instead of piperidine to the reaction mixture, a similar good result is obtained.

When replacing the acetonitrile by the equivalent amount of propionitrile, the 4.6-diamino- 2-ethyltriazine-l.3.5 is obtained.

Example? A mixture of 84.p arts of dicyandiamide, 250

parts of benzonitrile and about 8 parts of piperidine isheated for about 3 hours almostto the boiling point of the benzonitrile. 4.6-diamino- 2-phenyltriazine-1.3.5 (benzoguanamine) of the I formula:

crystallizes from the solution when pool. This product has a melting point of 222 and is-obtained in a yield of 85% of the throretical, whereas without the addition ofpiperidine only a product containing about per cent of melamine is obtained in a yield of about 40% of the theoretical.

The same result is obtained when heating to boiling a mixtureof 42 parts-of dicyandiamide, parts of benzonitrile, about parts of diethylbenzene and 4 parts of piperidine for about 3 hours. a

Instead of piperidine corresponding amounts of other compounds of a strongly basic character such as diethylenetriamine, pyrrolidine, tetrahydroquinoline or' potassium carbonate or so- A dium hydroxide maybe added.

When'replacingthe: benzonitrile by the equivalent amount of the'three isomeric chlorobenzonitriles or methylbenzonitriles the corresponding substitution products of vbenzoguanamine are obtained bearing, a chlorine atom or a methyl group .in the ortho-, metaor para-position of the benzene 'nucleus standing in the 2-position of the triazine ring.

Example 3 A mixture of 300 parts of ,B-naphthohitrile, 84 parts of dicyandiamide, 3.to 5 parts of piperidine (or pyrrolidine or henzylamine) is heated. while stirring at 200 to 205 for 3 to 4 hours. When cool the reaction mass is diluted with an organic solvent of a low boiling point such as carbon tetrachloride and the precipitate is filtered oil. The 4.6-dlamino-2-(2'-naphthyl) -triazine oi the iormula N thus obtained is a white powder having a melting point of 240 C. It is soluble in high boill5 ing solvents such as benzonitrile. The yield is the theoretical whereas without the addition of a basic agent there is obtained a substantially smaller yield of a product of an inaccurate melting point and only partly soluble in benzonitrile.

Example 4 A mixture of 84 parts of dicyandiamide, 250 parts of benzylcyanide and about 8 parts of piperidine is heated to boiling for about 3 hours. 4.6-diamino-2-benzyl-triazine-1.3.5 of the formula:

is obtained. The same is a colorless powder melting at 248- 250 0., soluble in hot water and scarcely soluble in alcohol and benzene.

We claim:

1. Improved process for producing guanamine derivatives of the general formula:

wherein R stands for a member of the group consisting of an alkyl and the benzyl radicle, an aromatic radicle of the benzene and naphthalene series and a heterocyclic radicle of the iurane series which consists in heating a mixture of dicyanamide, a nitrile compound of the formula RCN, wherein R has the aforesaid significance, and a strongly basic compound.

2. The process as defined in claim 1 wherein R is alkyl.

3. The process as defined in claim 1 wherein 'R is alkyl and wherein the strongly basic compound is a heterocyclic compound.

4. The process as defined in claim' 1 wherein R. is methyl and the strongly basic compound is piperidine.

5. The process as defined in claim 1 wherein R is an aryl of the benzene series.

6. The process as defined in claim 1 wherein R is phenyl and the strongly basic compound is piperidlne.

7. The process as defined in claim 1 wherein R is naphthyl and the strongly basic compound is piperidine. V

WERNER ZERWECK. WALTER BRUNNER. 

